generalized linear model

  1. W

    Link = log code won't work

    Hi, doing a generalised linear model with poisson distribution, here is my model code... model<-glm(carnivore_abundance~altitude_1+dist_stream+canopy_openess+basal_area+dist_large_river,family=poisson,data=main_data) really frustratingly whenever I try to add link=log is doesn't work it...
  2. R

    Structured Modeling or Multiple Models?

    We conducted a study in order to determine the factors that influenced turtle nest site selection. We collected various environmental variables from turtle nests, as well as three controls (i.e. locations not selected by turtles for nests). Positive controls (PC) were placed within 10m of a...
  3. E

    Generalized Linear Model: help interpeting interaction

    Hello! I apologise in advance if I missed it, but I couldn't find an answer in previous threads. I run a generalized linear model with 1 factor (gender) and 5 covariates. No single variable appears to have a predictive value on my VD. However, when I test for interactions, many seem to...
  4. J

    When to use Multivariable vs. Multivariate?

    Hi - I recently met with a statistician to discuss some of my data, and learned quite a bit, but was still left with some questions. I have learned that there is a difference between multivariable and multivariate data; however, I am not certain when to use each approach. I understand that...
  5. M

    Interpretation of GLM output for binomial family

    Hello everyone, I need help interpreting GLM output for binomial family and determining if this GLM is the correct one to use according to what I need to analyze. Noninvasive genetic sampling of a wild cat was conducted to determine sex. Different environmental factors were identified to...
  6. T

    Which kind of general linear model?

    Hello statisticians, Let me introduce myself. I am a 19 year old student Applied Economic Sciences at the University of Antwerp (Belgium). We are given a task for the course 'regression and anova' consisting of 5 questions. The first four questions were no problem but I'm stuck at the last...
  7. R

    Different p-values with different procedures

    Fairly novice in statistics, so this will surely have a simple explanation. I ran bivariate analyses to check for normality of a series of variables and also to test the relationship of each with two outcome variables (one binary the other continuous). In the bivariate analyses (using either...
  8. victorxstc

    Binary mixed-model logistic regression using lmer() of lme4 for multilevel analysis

    In my experiment, each patient has been observed twice, once using placebo and the other time using the real treatment. I want to assess the predictive effects of the treatment and patients' demographics (age, sex, etc.). Therefore I have for example 100 patients, but actually 200 pairs of...
  9. R

    Prediction interval of generalized linear models

    When doing predictions using a generalized linear model, how to get the prediction interval or prediction distribution? My model has a gamma distribution and a reciprocal link function in particular. Can anyone please help me on solving this by either analytical methods or simulation?
  10. R

    Prediction interval of generalized linear model

    I am trying to do predictions using a generalized linear model, and my model has a gamma distribution for the response variable and a reciprocal link function. Are there ways to obtain the prediction interval or prediction distribution by simulation? I couldn't find any software with such a...
  11. M

    Estimating Covariate Effects on Likert-Scale Response Data

    I am working on a problem where we elicit medical residents perceptions regarding the importance of specific core medical competencies (professionalism, collaboration, medical expertise, etc.) on a 5 point Likert scale. For example, "In your current residency role how important is...
  12. B

    Calculating effect size for generalized linear model?

    Hi, I have carried out a generalized linear model (in SPSS) with one dependent variable and two factors. Both factors have multiple categories (ie. one factor has three 'groups', the other four). I would like to calculate the effect size for each factor. I have found a lot of information...
  13. R

    generalized liner mixed model with categorical fixed effects?

    Hi Folks, I am running a generalized linear mixed model with a poisson distribution and a log link function in SPSS 19. My target/dependent variable is a continuous count and I am looking at how the count changes over time. Most of the variables I am using as fixed effects are continuous...
  14. J

    Linear mixed model without random or repeated effects? GLMZ?

    Hi, I'm working on a dissertation, of which many chapters have longitudinal data and I've been using linear mixed models to estimate growth. I also have some non-longitudinal data (i.e. cross-sectional) that I'd like to estimate growth with in a similar way. The cross-sectional data spans a...